Reinforced plastic energy absorber system and methods of making the same

ABSTRACT

In one embodiment, an energy absorber comprises: a plurality of crush lobes, wherein the base, sides and outer wall comprise a first thermoplastic material; and a composite insert in the energy absorber, wherein the insert comprises a second plastic material and reinforcement, and wherein the composite insert is a separate element that is disposed in located at an area of the crush lobes, wherein the area is the side and/or the outer wall, and wherein the area has an area height and an area width. In an embodiment, a corner energy absorber can comprise: a plurality of layers with a plurality of ribs connecting the layers, wherein the layers and ribs comprise a first thermoplastic material; a composite insert comprising a second plastic material and reinforcement, and wherein the composite insert is a separate element that is disposed in the layers, the ribs, or both.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/731,436, filed Jun. 5, 2015, which is a continuation of U.S.patent application Ser. No. 14/190,717, filed Feb. 26, 2014, which is adivision of U.S. patent application Ser. No. 12/915,673, filed Oct. 29,2010, the contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure relates generally to energy absorbers for use ina vehicle, for example, to reduce injuries (e.g., to occupant(s),pedestrian(s), etc.) and/or to reduce vehicle damage.

Increased importance has been placed on methods for minimizing theamount of injury suffered by a person during an impact with a movingvehicle as well as the amount of vehicle damage. Different regulatorycommittees assess automotive-pedestrian and occupant impact performanceglobally. Depending on the overall performance, vehicles are assigned acumulative safety rating. Each and every component of the vehicle needsto satisfy the specific impact criteria in order to ensure a goodoverall rating for the vehicle.

Due to the regulatory requirements and the desire to have, andcommercial advantages of having, a high overall safety rating, vehiclemanufacturers are continually adding components such as energy absorbersto the vehicle. Although energy absorbers generally provide safetybenefits and/or lesser insurance cost, they add some weight to thevehicle, and restrict styling freedom due to additional packaging spacerequirements. Hence, vehicle manufactures are continually striving forhigh performance energy absorber systems with reduced weight and/orpackaging space. Another approach has been to modify the geometricalconfiguration of an existing energy absorber design. However, thisapproach has not resulted in a significant weight change. These existinglow performance systems generally require large amounts of packagingspace to meet the impact regulations. A large packaging space, however,reduces the vehicle styling freedom. For example, many common energyabsorber systems include foam as the energy absorbing element. The foamsystems have lesser energy absorption efficiency (e.g., than injectionmolded plastic energy absorbers) and thus require more packaging spaceto absorb the same impact energy.

As a result, there is a continuing need to design an energy absorberthat will deform and absorb impact energy to attain a good vehiclesafety rating with a decreased weight and lower amount of packagingspace resulting in increased design freedom. Furthermore, sincedifferent vehicle platforms have different components, due to theirinherent geometry and assembly requirements, they require differentenergy absorber designs to satisfy the various impact criteria. Aflexible solution to this problem is sought.

BRIEF DESCRIPTION

Disclosed, in various embodiments, are energy absorbing devices that canbe used in conjunction with various vehicle components.

In one embodiment, an energy absorber comprises: a plurality of crushlobes, wherein the crush lobes include a base and sides extending fromthe base to an outer wall, wherein the base, sides and outer wallcomprise a first thermoplastic material; and a composite insert in theenergy absorber, wherein the insert comprises a second plastic materialand reinforcement, and wherein the composite insert is a separateelement that is disposed in located at an area of the crush lobes,wherein the area is the side and/or the outer wall, and wherein the areahas an area height and an area width.

In an embodiment, a corner energy absorber can comprise: a plurality oflayers with a plurality of ribs connecting the layers, wherein thelayers and ribs comprise a first thermoplastic material; a compositeinsert comprising a second plastic material and reinforcement, andwherein the composite insert is a separate element that is disposed inthe layers, the ribs, or both.

These and other non-limiting characteristics are more particularlydescribed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings wherein likeelements are numbered alike and which are presented for the purposes ofillustrating the exemplary embodiments disclosed herein and not for thepurposes of limiting the same.

FIG. 1 is a perspective view of an embodiment of an insert molded into awall of an energy absorber.

FIG. 2 is a prospective view of an embodiment of an energy absorber withinsert(s) located along a portion of the energy absorber between twowalls.

FIG. 3 is a prospective view of an energy absorber with an insertlocated in an underbar of the energy absorber.

FIG. 4 is a schematic illustration of an embodiment of a corner energyabsorber that can extend from the end of a bumper beam, wherein theenergy absorber comprises inserts.

FIG. 5 is a rear view of the corner energy absorber of FIG. 4 with aseparate view of the inserts included therein.

FIG. 6 is a schematic illustration of an embodiment of an energyabsorber having inserts located on various crush lobes of the energyabsorber.

FIG. 7 is an expanded view of a group of crush lobes from the energyabsorber of FIG. 6.

FIG. 8 is a schematic illustration of an embodiment of a mold forforming an energy absorber having an insert.

FIG. 9 is a prospective view of an embodiment of an energy absorberwithout composite inserts.

FIG. 10 is a prospective view of an embodiment of an energy absorberhaving the same materials and design as the energy absorber of FIG. 9except with composite inserts on the side walls.

FIG. 11 is a top view of the energy absorber of FIG. 10.

FIG. 12 is a Knee Acceleration versus Time plot for the energy absorbersillustrated in FIGS. 9 and 10.

DETAILED DESCRIPTION

Energy absorbers protect an individual and/or vehicle component byabsorbing energy when a particular vehicle component is impacted.Therefore, during an impact at the location of a particular vehiclecomponent, the impact energy can be absorbed by the energy absorber,thereby protecting the vehicle component, pedestrian, and/or occupant.When the energy absorber is separately demountable from the vehiclecomponent, after the impact, if the energy absorber was able to absorb asufficient amount of the impact energy, the energy absorber can bereplaced without requiring the replacement of the vehicle component.Since the energy absorbers are designed to undergo plastic deformation(and optionally elastic deformation), they absorb energy upon impact,thereby reducing the damage to the pedestrian, occupant, and/or vehicle,accordingly. The energy absorbers can therefore reduce maintenance costof the vehicle after impact.

It is clearly understood that the problems of reduced weight and greaterdesign flexibility for energy absorbers are much greater than merelymaking thinner components or interchanging materials. Such solutionsadversely affect performance such that the components no longer functionas intended, failing to meet the requisite standards. Merelyinterchanging materials is insufficient in meeting the industriesrequirements for energy absorption, structural integrity, durability,design flexibility, and weight. Metals are heavy and, for example, donot have the desired energy absorption capabilities for the second ormultiple impact cases. Plastics are lighter than metals, but, by nature,are softer and therefore may require higher thickness to attain the samestrength, wherein the thicknesses are limited by tooling, and space.Furthermore, weight benefits gained by using a plastic can be lost ifvery thick components are required.

Disclosed herein, in various embodiments, are energy absorbers which canbe used in conjunction with vehicle components, e.g., to minimize thevehicle damage and/or injury suffered in an impact. The energy absorberscomprise reinforced composite insert(s) (e.g., the insert(s) are locatedat (i.e., in or on) the side and/or outer wall of the energy absorber).The inserts enhance the structural integrity of the energy absorber,thereby tuning the energy absorption capabilities thereof, at theparticular location. Hence insert(s) can be used at the crush lobe(s),the support structure (e.g., if the metal bumper beam has been replacedwith a plastic support structure), and/or the crush can(s). In some ofthe embodiments, the insert is located in a portion of the energyabsorber that extends in the z direction (See FIG. 7), for example, itextends away from the vehicle.

The insert can comprise a single or multiple layers, wherein theindividual layers can have the same or different thicknesses and/orproperties. Different lamination angles can also be employed. Forexample, an insert can have a sandwich structure with face and core ofsimilar and/or dissimilar materials, as well as with functionally gradedproperties. In some embodiments, the insert can comprise a material thataligns more along one axis than another, e.g., the alignment axis. Thevarious layers can then be stacked such that the alignment axis of onelayer is at a different angle than the alignment axis of another layer(e.g., of an adjacent layer). For example, the layers can alternate 0degrees, 90 degrees, 0 degrees, etc. (e.g., such that the alignment axisof one layer is perpendicular to the alignment axis of the adjacentlayer). Other angles are also possible, e.g., 45 degrees, and so forth.The specific number of layers and the orientation of each layers'alignment axis is dependent upon the desired stiffness of thatparticular insert. Inserts employed in different portions of the energyabsorber can have a different stiffness, as is desired for theparticular location. In some embodiments, the insert comprises greaterthan or equal to 3 layers, specifically, 3 to 10 layers, morespecifically, 4 to 7 layers. Optionally, the layers can have alternatingalignment axes, such as alternating between 0 degrees and 90 degrees.

Because these inserts are separate elements (e.g., separate from theother components of the energy absorber as opposed to an element formedin situ with the remainder of the energy absorber), they can bestrategically located in desired areas of the energy absorber. In otherwords, the insert does not need to be located throughout the energyabsorber, unlike a reinforcement that is mixed into the plastic formingthe energy absorber. The inserts can be strategically located in some orall of the side walls (e.g., the walls extending from the base to theouter wall of a crush lobe), and/or in the end wall(s), and/or in theouter wall(s), and/or in various rib(s), and/or extensions (for example,see rib 48 in FIG. 5, and side walls 86, end walls 88, and outer wall 82in FIG. 10).

Use of the insert(s) can enable strategic reinforcement of the energyabsorber. The strategic reinforcement enables (i) reduction of theoverall weight of the energy absorber, (ii) reduction of the overallsize of the energy absorber, and/or (iii) increase in the ability of theenergy absorber to absorb energy upon impact. Increased energyabsorption reduces vehicle damage and/or injury to occupants and/orpedestrians during an impact. The reduced weight and/or increasedperformance allows for increased design freedom for the automotivemanufacturer because less packaging space is required with an energyabsorber having a reduced weight and/or increased performance. In otherwords, the same performance levels can be attained in a reduced amountof space by using the present inserts. The energy absorbers describedherein can improve system performance up to 40% (e.g., for low speedvehicle damageability requirements like Insurance Institute for HighwaySafety (IIHS) impact regulations and/or lower leg safety requirementsfor pedestrian impact) and/or reduce the system weight and hence, systemcost up to 30% (when compared to conventional plastic energy absorbers,meeting same criteria in same packaging space). Essentially, compositeinsert reinforcement in an energy absorber increases the efficiency ofenergy absorption and can help reduce the energy absorber depth (alongvehicle axis; e.g., distance the absorber extends out from the vehicle(z direction)) by 20 to 30% compared to the same design and compositionenergy absorber without insert(s). In other case for same packagingspace, an energy absorber with composite insert reinforcement improvesthe impact performance by 15 to 30% or more, compared to the same designand composition energy absorber without insert(s). The energy absorberscan also reduce the packaging space of the energy absorber in a vehiclecomponent.

The energy absorbers comprise an insert that increases stiffness (ascompared to the same thickness area and absorber material, but withoutthe insert). The insert can be located at an area of the energy absorber(e.g., on a surface, extending into a wall, or between surfaces (e.g.,in a wall)). The insert can provide relatively high stiffness without anincrease or only a small increase (i.e., less than or equal to 1%) insystem weight. For weight considerations, the inserts can be located inareas requiring greater stiffness in order to meet safety and/or energyabsorption requirements, while not located in other areas. This enablesa reduced thickness of the materials in the high stiffness areas withoutincreasing weight in lower stiffness areas. During an impact, the energyabsorbers comprising these inserts absorb significantly more energy thanthe energy absorber wall in contact with the inserts, or than a wall, ofthe same wall material and a thickness that is equal to the combinedwall and insert thickness.

The specific dimensions of the energy absorber and the inserts thereinare dependent upon its location in the vehicle and its function. Forexample, the insert's length and width will be dependent upon the amountof space available in the desired location of use. The depth and wallthicknesses (e.g., the distance between the supporting walls) will bedependent upon the available space, the desired stiffness, and thematerials (or combination of materials) employed. The insert can havevarious sizes, number of layers, materials, and shapes, depending uponthe desired location in the energy absorber. An exemplary shape includesa planar strip. Although the thickness of the insert will be dependentupon the particular energy absorption requirements for the particularlocation, generally, the insert can have a thickness of less than orequal to 10 millimeters (mm), specifically, 0.2 mm to 5 mm, morespecifically, 0.5 mm to 3 mm. For example, when used as part of a crushlobe for a pedestrian energy absorber (e.g., impact speeds of 40kilometers per hour (km/hr) lower leg impact and desired energyabsorption of approximately 450 Joules), the insert thickness can be 0.2mm to 5 mm, specifically 0.5 mm to 3 mm. When used as part of a crashcan for vehicle impact (e.g., energy absorption of up to approximately4,000 Joules), the insert thickness can be 0.2 mm to 5 mm, specifically0.5 mm to 3 mm.

The insert is a composite material, e.g., reinforcement and plastic, andcan comprise any plastic material(s) having the desired characteristicsfor the particular application (e.g., location) of the energy absorberin the vehicle. The reinforcement can be comprise plastic, metal,ceramic, glass, wood, and/or natural and synthetic composite material,and so forth, as well as combinations comprising at least one of theforegoing. For example, reinforcement material can be glass, carbon,titanium, aluminum, stainless steel, talc, mica, as well as combinationscomprising at least one of the foregoing. The form of the reinforcementcan be fibers (including woven, nonwoven (e.g., felt), chopped, in,and/or random fibers), flakes, beads, particles, and combinationscomprising at least one of the foregoing forms of reinforcement. Forexample, the composite inserts can comprise continuous fibers.Alternatively, or in addition, discontinuous long and/or short fiberscan be used.

Exemplary characteristics of the plastic material can include hightoughness/ductility, thermal stability, high energy absorption capacity,a good modulus-to-elongation ratio, and recyclability, among others,wherein “high” and “good” are intended to mean that the characteristicat least meets vehicle safety regulations and requirements for the givencomponent/element. The plastic material used for the insert comprises adifferent plastic material than the portion of the energy absorbercomprising the insert, and is a material compatible therewith. Theplastic of the insert can be thermoplastic, thermoset, or a combinationcomprising at least one of the foregoing plastic materials. Exemplaryplastic materials include thermoplastics such as polybutyleneterephthalate (PBT); acrylonitrile-butadiene-styrene (ABS);polycarbonate; polycarbonate/PBT blends; polycarbonate/ABS blends;copolycarbonate-polyesters; acrylic-styrene-acrylonitrile (ASA);acrylonitrile-(ethylene-polypropylene diamine modified)-styrene (AES);phenylene ether resins; blends of polyphenylene ether/polyamide;polyamides; phenylene sulfide resins; polyvinyl chloride PVC; highimpact polystyrene (HIPS); low/high density polyethylene (L/HDPE);polypropylene (PP); expanded polypropylene (EPP); and thermoplasticolefins (TPO). One commercially available material that can be used forthe energy absorber is Xenoy®, which is commercially available fromSABIC Innovative Plastics IP B.V. An exemplary thermoset material thatcan be used to form the insert is epoxy. Some exemplary inserts comprisePBT and fibers (e.g., metal, glass, or carbon), or polycarbonate andceramic filler, or a plastic material and a woven mat, or a continuousfiber in an epoxy matrix (such as a continuous carbon fiber in an epoxymatrix).

The energy absorber can be made from a thermoplastic material and cancomprise combinations comprising at least one of any of theabove-described plastic materials. The material can optionally furtherinclude reinforcement distributed therethrough, such as fibers, pellets,flakes, particles, and so forth, as well as combinations comprising anyof the foregoing.

The insert can comprise Young's modulus values of 0.05 E⁺⁰⁵ MPa to 2E⁺⁰⁵ megaPascals (MPa), along the three principle axis, specifically,0.5 E⁺⁰⁵ MPa to 1.5 E⁺⁰⁵ MPa along the principle axis, and 0.05 E⁺⁰⁵ MPato 0.10 E⁺⁰⁵ MPa along the other two axis. The Shear modulus valuesalong the three principle axis can be 4.0 E⁺⁰³ MPa to 7.0 E⁺⁰³ MPa,specifically, 5.0 E⁺⁰³ MPa to 6.0 E⁺⁰³ MPa. Poisson's ratio (“υ”) can be0.2 to 0.4, specifically, 0.25 to 0.35. The density can be 1,200kilograms per cubic meter (kg/m³) to 1,700 kg/m³, specifically, 1,450kg/m³ to 1,650 kg/m³. In an exemplary embodiment, the insert cancomprise Young's modulus values of 1.2 E⁺⁰⁵ MPa, 0.079 E⁺⁰⁵ MPa, and0.079 E⁺⁰⁵ MPa along the three principle axis, Shear modulus valuesalong the three principle axis can be 5.5 E⁺⁰³ MPa, Poisson's ratio of0.3, and a density of 1,580 kg/m³.

The insert can comprise one or multiple layers oriented in the same ordifferent directions. For example, each layer can be oriented in adifferent direction with respect to the adjacent layer. For example,each layer can be oriented perpendicular to the adjacent layer, such asa first layer can be oriented at 0 degrees, a second layer oriented at90 degrees, a third layer oriented at 0 degrees, and so forth, dependingupon the desired number of layers. The number of layers is not limitedand can comprise any number of layers that will provide the desiredimpact and performance properties. The insert (composite) layup can be amultilayer cross-ply, angle-ply composite, and/or sandwich configuration(e.g., with stiffer faces and a weaker core). Additionally, the degreeof orientation of the layers is not limited and can be any range ofdiffering degrees of orientation between 0 degrees and 90 degrees.

The insert(s) can be located anywhere along the energy absorber and canbe located at an area of the energy absorber (i.e., on the surface, intoa surface, or within an area (e.g., encapsulated inside a wall)). Inorder to avoid separation of the insert from the area, or dislodging ofan insert (e.g., during an impact), in some embodiments, the insert islocated within the wall (e.g., is insert molded into the wall during themolding of the component).

The energy absorbers comprising the insert(s), which can have an openconfiguration (e.g., open in the back (such as in the z direction on theside opposite the impact side; see FIGS. 5 and 7), or open in the topand/or bottom (y direction; see element 28 in FIG. 2)) or closedconfiguration, and have a side (e.g., outer wall) oriented to besubjected to impact. Another side of (e.g., base) the energy absorbercan be located adjacent to a stiffer support so as to be crushable,e.g., located adjacent or attached to a base (such as a stiff base likethe body in white (BIW), the bumper beam, or another automotivecomponent). In some embodiments, the energy absorber is attached to thevehicle only at specific points (e.g., only attached to the two siderails, yet extending across the front of the vehicle).

A more complete understanding of the components, processes, andapparatuses disclosed herein can be obtained by reference to theaccompanying drawings. These figures (also referred to herein as “FIG.”)are merely schematic representations based on convenience and the easeof demonstrating the present disclosure, and are, therefore, notintended to indicate relative size and dimensions of the devices orcomponents thereof and/or to define or limit the scope of the exemplaryembodiments. Although specific terms are used in the followingdescription for the sake of clarity, these terms are intended to referonly to the particular structure of the embodiments selected forillustration in the drawings, and are not intended to define or limitthe scope of the disclosure. In the drawings and the followingdescription below, it is to be understood that like numeric designationsrefer to components of like function.

FIG. 1 illustrates an embodiment of a portion 10 of an energy absorber,e.g., illustrates the outer wall of an energy absorber such as the outerwall of a crush lobe (see FIG. 6), or a side wall of a crush lobe (seeFIG. 10). This Figure shows an insert 14 molded into an energy absorberwall 12, while FIG. 10 shows the insert molded into the side wall of thecrush lobe. The portion 10 can form any part of the energy absorberwhere enhanced impact strength is desired, such as a wall, (e.g., outerwall, side, rib, end(s), and/or connectors), base (e.g., /or base of acrush lobe), and so forth.

Furthermore, the insert can provide reinforcement to any desired area ofthe portion 10, such as less than or equal to 90% of the volume of thearea comprising the insert (e.g., as less than or equal to 90% of thevolume of the wall) can be insert, specifically, less than or equal to65%, and more specifically, less than or equal to 50%. In someembodiments, the insert can have a height that is less than or equal to90% of the height of the area portion of the component comprising theinsert (e.g., see height “h” of side wall 86, FIG. 11), specifically,20% to 70%, more specifically, 30% to 50%.

In various embodiments, the insert can have a depth that is greater thanor equal to 20% of the depth (thickness) of the area (e.g., the portionof the component comprising the insert), specifically, greater than orequal to 50%, more specifically, greater than or equal to 65%, yet morespecifically, 25% to 98%, even more specifically, 45% to 80% of thedepth of the area.

In various embodiments, the insert can have a width (e.g., as isillustrated by line “w” in FIG. 1) that is greater than or equal to 30%of the width of the area of the component comprising the insert (e.g.,portion 10), specifically, greater than or equal to 50%, morespecifically, greater than or equal to 75%. Specifically, the insertwidth can be 30% to 100% of the width of the area, more specifically,35% to 90% of the area width, yet more specifically, 40% to 65% of thearea width.

Turning now to FIG. 2, illustrated is a lower spoiler component 20 thatcan provide lower leg support for more balanced energy absorption andimproved rotation performance. The spoiler (e.g., energy absorber 20)comprises a first portion 22 designed to be between a second portion 24(outer element that can contact the lower leg in an impact) and the bodyin white (“BIW”). As is illustrated, insert(s) 26 can be located at thesecond portion of the energy absorber, as a strip that extends at thesecond portion, or as a plurality of separate pieces strategicallylocated at the second portion. The energy absorber 20 illustrated inFIG. 2 is configured for pedestrian protection upon impact, such thatreduced forces to the pedestrian (e.g., reduced force to the knee regionand/or lower leg region of the pedestrian) are observed upon an impact.

FIG. 3 illustrates another embodiment, where an energy absorber 30comprises an underbar 32 with an insert 34 located on the underbar.Similar to the lower spoiler, the underbar illustrated in FIG. 3supports the lower leg of a pedestrian during an impact, and reducingthe rotation of the leg. The underbar comprises extensions 36 that areconfigured to connect the underbar 30 to the bumper beam and/or to andenergy absorber attached thereto. The underbar can be a plasticcomponent, hollow from the back, with inserts in along the front edge,or along walls extending from the open end to the front wall.

Now referring to FIGS. 4 and 5, a corner energy absorber 40 extendingfrom an end of a bumper beam 38 is illustrated. The energy absorber 40has an extension 42 that extends into the end of the bumper beam (i.e.,into the hollow portion of the bumper beam) as illustrated in FIG. 4.The energy absorber 40 can comprise a multi-layer structure with theinserts 44 interspersed at the layers and/or ribs of the energy absorber40 (see FIG. 5 which is a rear prospective view of the energy absorber40 of FIG. 4). The multi-layer structure can comprise a number ofhorizontal layers 46 connected by a number of vertically extending ribs48, with inserts disposed at the layers and/or ribs. As is illustrated,the rib 62 that will abut the bumper beam 38 (e.g., it will abut theedge of the bumper beam 38) when the extension 42 is inserted into theend of the bumper beam 38. Additionally, layers 46, or portions thereof,can also comprise insert(s) 44. For example, the portion of the layers46 that are adjacent rib 62, on a side to be located outside of the beam38 (e.g., that are not a portion of the extension 42; e.g., are betweenrib 62 and the next subsequent rib) can comprise insert(s).

The number of layers, ribs, and inserts is not limited and can be basedupon desired energy absorption characteristics. The size and shape ofthe inserts 44 is also not limited and can be any size and shape thatwill provide maximum protection to the vehicle structure and componentsupon an impact. For example, the inserts can comprise a shape selectedfrom the group consisting of square, rectangular, circular, triangular,elliptical, hexagonal, pentagonal, etc., and combinations comprising atleast one of the foregoing. The energy absorber 40 illustrated in FIG. 4can be designed to take into account the low speed vehicle damageabilityrequirements for outboard impact to the vehicle bumper, like IIHS andFederal Motor Vehicle Safety Standards (FMVSS) impact requirements. Forexample, the inserts 44 can be configured to satisfy the 15% overlapbumper like barrier impact of IIHS bumper test protocols.

FIG. 6 illustrates an embodiment of a dual stage energy absorberdesigned to meet low speed vehicle damageability and pedestrian lowerleg impact requirements. The energy absorber 50 comprises a frame 54 towhich crush boxes 52 are attached at either end or both thereof, withcrush lobe(s) 56 located across the energy absorber 50 (e.g., betweenthe crush boxes 52). A plurality of crush lobes 56 extend outwardly fromthe frame 54. These crush lobes 56 help in cushioning the knee of lowerleg during the impact, whereas smaller stiffer crush boxes at the endsof the plurality of crush lobes 56, plays the key role for low speedimpacts to vehicle. The crush lobes 56 can vary in size and thicknessacross the length of the frame to enable the energy absorber 50 toabsorb the maximum desired amount of energy upon an impact. The crushlobes 56 can comprise an outer wall 60 that is spaced from the frame 54a distance equal to an extending wall 62. The inserts 58 can be locatedon some or all of the outer walls 60 of the crush lobes 56 (e.g., can bedisposed on the outer walls in an alternating fashion (e.g., every othertwo crush lobes comprises inserts) or in specific locations, (e.g., inthe center crush lobes, in the outer most crush lobes, and/or in crushlobes near the ends of the plurality of crush lobes)).

In some embodiments, the crush lobe 56 can comprise a greater thicknessat the outer wall 60 than at the frame 54 and the outer wall 60 of thecrush lobe 56 can comprise a smaller cross sectional area than the base64 of the crush lobe 56 attached to the frame 54. The inserts 58 allowthe energy absorber 50 to provide significantly less load on the lowerleg or knee of a pedestrian at substantially the same or only a slightlyincreased weight (e.g., less than or equal to a 1% increase in weight).This allows for a reduction in the packaging space required of theenergy absorber, which enables more freedom for varying styles anddesigns to the automotive manufacturer.

As is illustrated in FIGS. 6 and 7, the crush lobes can have a singleextending wall 62, or multiple walls with gap(s) therebetween to enablethe crush lobe(s) to have the desired crush characteristics at theparticular location. Also illustrated are insert(s) employed withselected crush lobes and not employed with others, again enabling tuningof the crush characteristics. For example, inserts can be employed onsubstantially “U” shaped crush lobes, wherein there is no extending wallon two opposite sides of the lobe and are extending walls on the othertwo extending walls, with the insert employed with the outer wall thatconnects the two extending walls. Optionally other crush lobes can bedispersed between the insert crush lobes. These other crush lobesoptionally comprise extending walls on greater than or equal to 3 sidesof the crush lobes, extending from the base to the outer wall.

FIG. 9 illustrates the pedestrian energy absorber without compositeinserts, while FIG. 10 illustrates the same design of energy absorber asFIG. 9, except with composite inserts. Composite inserts arestrategically placed in top and bottom load carrying walls of thisenergy absorber device to help attain controlled crushing of the energyabsorber and better energy absorption in less packaging space. Here theenergy absorbers are illustrated as having a height that is 15% to 25%of the area height (e.g., area 86), and a width that is 70% to 90% ofthe area width.

The energy absorber can be produced by several methods such as molding(e.g., over-molding), forming, or any other suitable manufacturingtechnique. For example, the energy absorber can be molded via insertinjection molding with the insert placed in the injection molding cavity(e.g., with slight tool modification or redesign). The energy absorbercan be made as a one-piece structure or as several components which areassembled together. For example, the crush wall(s) and support wallscould be made separately then joined together by any suitable joiningtechnique (e.g., adhesive, bonding, fastener(s) (such as a bolt, screw,clamp, snap-connector, and so forth)). In some embodiments, the energyabsorber can be thermoformed as a single component. In some embodiments,the energy absorber can be injection molded as a single component.

One method for forming the energy absorber is illustrated in FIG. 8where a mold 70 comprises an upper mold portion 72 and a lower moldportion 74. Inserts 76 are illustrated in the opening between the uppermold portion 72 and the lower mold portion 74, e.g., with the help ofholding pins (76A) as shown in FIG. 8. Inserts 76 can be placed into themold cavity and molded to the energy absorber there with slight designor tool modification. The energy absorbers and inserts can be processedby insert injection molding, thermoforming, blow molding, as well ascombinations comprising at least one of the foregoing. The inserts canbe enclosed within the material comprising the energy absorber on bothsides (e.g., the front and the back) or only one side (e.g., the frontor the back). With the insert molding process, the insert becomes anintegral part of the energy absorber.

The energy absorber is further illustrated by the following non-limitingexamples.

EXAMPLES

Various energy absorbers in all of the examples were evaluated with CAEstudies (simulations) to compare impact performance of the hereindescribed energy absorbers comprising an insert with energy absorbersthat did not comprise an insert. Throughout the examples, the insert wascut from a 2 mm thick sheet of a laminated five layer (0°-90°-0°-90°-0°)lay-up of a three-dimensional weave of continuous carbon fiber in anepoxy matrix.

Example 1 Pedestrian Protection

Table 1 illustrates the performance summary for lower leg impact on ageneric vehicle platform with a lower spoiler design corresponding toFIG. 2. In Table 1, a lower spoiler made from glass filled polyimide(Sample 1) and a lower spoiler made from Xenoy® resin (Sample 2),neither comprising an insert were compared with an energy absorber madefrom Xenoy® resin comprising an insert (Sample 3) and an energy absorbercomprising an insert that spanned the full width of the vehicle front(Sample 4). Sample 1 and 2 had no inserts, and Sample 3 had an insert atthe center of the front face of lower spoiler (the insert had a heightthat was about 80% of the wall height and extended the full length ofthe outer wall), as is shown in FIG. 2.

The vehicle bumper system incorporating proposed lower spoiler isimpacted with a commercially available lower leg model and a kneeacceleration model, i.e., G-load in units of gravity (G), knee bending(i.e. rotation in degrees (deg)), and tibia shear in millimeters (mm)are estimated by CAE model using LS-DYNA software (commerciallyavailable from Livermore Software Technology Corp, California, USA).Desirably, the maximum rotation should not exceed 15 degrees, themaximum G load refers to the load on knee or lower leg of a pedestrianupon impact and the maximum acceptable value is 150. The maximum shearshould not exceed 6 mm and the maximum rotation should not exceed 15degrees.

TABLE 1 System Composite Max. Max. Sample Weight Insert Weight Max. GRotation Shear No. (kg) (kg) Load (Degrees) (mm) 1 polyimide-lower 1.16N/A 151.1 9.1 1.9 spoiler 2 Xenoy ® resin lower 1.01 N/A 108.4 15.5 2.8spoiler 3 Xenoy ® resin lower 0.85 9.50 × 10⁻⁴ 99.9 13.4 2.9 spoilerwith composite insert 4 Xenoy ® resin lower 0.88 0.039 98 12.9 2.9spoiler with composite insert over full span of vehicle

Table 1 illustrates a significant reduction in weight for Samples 3 and4 compared to Samples 1 and 2. Samples 3 and 4 demonstrated acceptablerotation values (less than 15 degrees) and comparable shear values ascompared to Samples 1 and 2 even with the lower weight values of Samples3 and 4. For example, Sample 3 contained 16% less weight than Sample 2and 27% less weight than Sample 1, while Sample 4, which spanned thefull width of the vehicle front, contained 9% less weight than Sample 2and 21% less weight than Sample 1. Additionally, the maximum G load issignificantly less with Samples 3 and 4 than Samples 1 and 2, indicatingthat a pedestrian will suffer less force upon an impact when an insertis used due to the insert absorbing more of the energy upon impact ascompared to energy absorbers that do not contain the inserts.

Table 2 illustrates the performance summary for lower leg impact on ageneric vehicle platform with an underbar design corresponding to FIG.3. Sample 5 was made from Xenoy® resin with no insert and Sample 6 wasmade also made from Xenoy® resin but also contained the insert. The sameproperties as discussed above with respect to Samples 1 to 4 weremeasured using the same procedures and equipment.

TABLE 2 Max. Max. Sample Weight Max G Rotation Shear No. (kg) Load(Degree) (mm) 5 Xenoy ® resin Underbar 1.5 119.9 11.9 1.7 6 Xenoy ®resin Underbar 1.26 99.3 12.8 2.9 with composite insert

Sample 6 contained a reduction in weight of 16% but demonstratedcomparable maximum rotation values (12.8 for Sample 6 versus 11.9 forSample 5) and comparable shear values. Samples 1 through 6 illustratethat energy absorbers containing an insert and designed to have a lowerweight than comparable energy absorbers can perform the substantiallythe same or better than energy absorbers that do not contain an insert.However, the energy absorbers comprising an insert due to the decreasedweight cost less to produce and/or replace. Samples 1 through 6 alsoillustrate that the energy absorber weight can be reduced significantlywithout compromising the performance of the structure upon theapplication of an impact.

Example 2 Vehicle Damageability

Table 3 illustrates the performance summary for an IIHS bumper likebarrier with a 15% overlap on a generic vehicle platform with aninjection molded corner energy absorber corresponding to FIGS. 4 and 5.Samples 7 and 8 were both injection molded. The corner energy absorberextended from both the end of a bumper beam. The corner energy absorberhas an extension that extended into the end of the bumper beam (i.e.,into the hollow portion of the bumper beam) as illustrated in FIG. 4.The energy absorbers in Samples 7 and 8 contained extensions on the endsof the energy absorbers designed to absorb energy upon impact. Sample 8comprised inserts on the extensions. The inserts were set in the designillustrated in FIGS. 4 and 5. The vehicle bumper system incorporating aproposed corner energy absorber is impacted with a commerciallyavailable ‘Bumper like barrier for IIHS protocols’ and a Force in unitsof kiloNewtons (kN) and intrusion in millimeters (mm) are estimated byCAE model using the LS-DYNA software. Maximum intrusion refers to theamount the energy absorber impacts into the vehicle when there is acollision. The maximum force should generally be below 60 kN.

TABLE 3 Composite Max. System Insert Max. Intru- Sample Weight WeightForce sion No. (kg) (kg) (kN) (mm) 7 Xenoy ® corner EA with 0.51 N/A16.2 122 extensions 8 Xenoy ® corner EA with 0.49 0.025 32.6 76.2extensions and composite insert on extensions

Sample 8 contained 1% greater weight than Sample 7, but demonstrated asignificant improvement in the maximum intrusion into the vehicle uponimpact of 38% less than Sample 7 and an acceptable maximum force value.Sample 8 demonstrates that with the inserts located on the extensionsless intrusion into the vehicle occurs, which translates to a lowerrepair cost. Additionally, the initial cost of the energy absorber ofSample 8 should be similar to that of Sample 7, since Sample 8 onlycontained 1% greater weight than Sample 7.

Example 3 Dual Stage Energy Absorber

Tables 4 and 5 illustrate the performance summary for a Xenoy® resinenergy absorber designed for global use for lower leg impact performanceand low speed vehicle damageability on a generic vehicle platform, asdescribed in U.S. Pat. No. 7,568,746. The maximum G load, maximumrotation, and maximum shear were measured as described above withrespect to Samples 1 to 6. Each of Samples 9 to 12, 13, and 15 occupied85 mm of packaging space, while Samples 14 and 16 only occupied 80 mm ofpackaging space. Samples 10, 12, 14, and 16 each contained an insert asshown in FIGS. 6 and 7, while Samples 9, 11, 13, and 15 did not. Y0 isthe impact at center of the vehicle bumper along the width and Y264 isan impact 264 mm outboard from center of the vehicle.

TABLE 4 System Composite Max. Max. Sample Weight Insert Weight Max. GRotation Shear No. (kg) (kg) Load (Degree) (mm) Y-0 Impact Location 9Xenoy ® resin 0.92 N/A 141.5 15 1.5 Dual stage EA (85 mm)* 10 Dual stageEA 0.92 0.025 130.1 15 1.5 with composite insert (85 mm)* Y-264 ImpactLocation 11 Xenoy ® resin 0.92 N/A 158.6 15.8 1.7 Dual stage EA (85 mm)*12 Dual stage EA 0.92 0.025 132.6 15.7 1.3 with composite insert (85mm)* *This value indicates the packaging space.

TABLE 5 Composite System Insert Max. Max. Max. Sample Weight Weight GRotation Shear No. (kg) (kg) Load (Degree) (mm) Y-0 Impact Location 13Xenoy ® resin 0.89 N/A 141.5 15 1.5 Dual stage EA (85 mm)* 14 Dual stageEA 0.89 0.025 141.8 15.6 2 with composite insert (80 mm)* Y-264 ImpactLocation 15 Xenoy ® resin 0.89 N/A 158.6 15.8 1.7 Dual stage EA (85 mm)*16 Dual stage EA 0.89 0.025 146.9 16.4 1.8 with composite insert (80mm)* *This value indicates the packaging space.

Samples 10 and 12 demonstrate a significant improvement in performancepertaining to the maximum G load or the force exerted on a pedestrianduring an impact. Sample 10 had an 8% improvement compared to Sample 9,while Sample 12 had a 16% improvement compared to Sample 11 with only a0.1% increase in weight due to the inserts. Sample 11 demonstrated anunacceptable maximum G load of 158.6. Samples 14 and 16 showed similarresults even with a 5 mm or 6% reduction in packaging space with only a0.1 increase in weight due to the inserts. Here the data shows thecomparative performance of energy absorbers with and without inserts.

Example 4 Pedestrian Protection

Table 6 illustrates the performance summary for lower leg impact on ageneric vehicle platform with an energy absorber design corresponding toFIG. 10. In Table 6, an energy absorber made from Xenoy® resin iscompared with an energy absorber made from Xenoy® resin comprising aninsert. A vehicle bumper system incorporating the proposed energyabsorber is impacted with a commercially available lower leg model and aknee acceleration model, i.e., G-load in units of gravity (g), kneebending (i.e. rotation in degrees (deg)), and tibia shear in millimeters(mm) are estimated by CAE model using the LS-DYNA software.

TABLE 6 Max. Max Sample G-Load Rotation No. (G) (degrees) 17 Xenoy ®resin pedestrian EA 152 16 18 Xenoy ® resin Pedestrian EA 124 14.2 withcomposite inserts

Sample 18 demonstrates a significant improvement in performancepertaining to the maximum G load or the force exerted on a pedestrianduring an impact and knee bending, i.e., rotation. This is graphicallyillustrated in FIG. 12, wherein line 102 is Sample 18, and line 100 isSample 17. Incorporating inserts in the energy absorber helpscontrolling the crushing of load walls of the energy absorber, whichincreases the energy absorption in same packaging space and reduces theG-load and rotation values.

The energy absorbers disclosed herein comprising an insert offer a lowcost, high performance solution to the challenges facing automobilemanufacturers. The energy absorbers comprising an insert offer similaror even improved performance at lower or only slightly higher weights.With the energy absorbers having reduced weight with the inserts,substantially similar or even greater impact resistance and/orprotection to a pedestrian can be observed. With the energy absorbershaving the same or a slightly increased weight with the inserts,packaging space can be reduced with an increase in impact performance.

In one embodiment, an energy absorber, comprises: a plurality of crushlobes that deform plastically upon impact to absorb energy, wherein thecrush lobes include a base and sides extending from the base to an outerwall, wherein the base, sides and outer wall comprise a first material;and a composite insert in the energy absorber, wherein the insertcomprises a second plastic material and reinforcement, wherein thesecond plastic material is different than the first thermoplasticmaterial, wherein the insert is located at an area of the crush lobes,and wherein the area is the side and/or the outer wall.

In another embodiment, an energy absorber comprises: a plastic frame;thermoplastic crush lobes extending from the frame, wherein the crushlobes comprise an outer wall, an extending wall, and a base; and aplastic insert located at an area having a volume of the crush lobes,wherein the insert occupies less than or equal to 90% of the areavolume. The insert comprises a reinforcement and a plastic materialdifferent than the thermoplastic crush lobes.

In one embodiment, a vehicle comprises: the energy absorber assembly anda fascia covering the energy absorber assembly.

In another embodiment, a vehicle, comprising: energy absorber assemblyand a fascia covering the energy absorber assembly. The energy absorberassembly comprises a plurality of plastic crush lobes that deformplastically upon impact to absorb energy, wherein the crush lobesinclude a base and a side extending from the base to an outer walllocated on an end of the side opposite the base, wherein the base, sideand outer wall comprise a first material; a composite insert comprisinga second plastic material and reinforcement, wherein the second plasticmaterial is different than the first thermoplastic material, wherein theinsert is located at the side and/or the outer wall; crash cans locatedat each end of the energy absorber; and a composite insert located atthe crash can and/or at crush lobe. The energy absorber assembly isconnected to vehicle rails.

A method of making an energy absorber, comprising: insert molding athermoplastic energy absorber comprising crush lobes having a base andan outer wall, with sides extending from the base to the outer wall,wherein a reinforced plastic insert is located in at least one thesides.

In the various embodiments: (i) the reinforcement can comprisecontinuous fibers; and/or (ii) the area can have a volume and whereinthe insert occupies less than or equal to 65% of the volume; and/or(iii) the area can have a height “h”, a thickness, and a width “w”, andwherein the insert has an insert height that is less than or equal to90% of the area height, and has an insert width that greater than orequal to 30% of the area width; and/or (iv) the insert height is 20% to70% of the area height and the insert width is 40% to 75% of the areawidth; and/or (v) the reinforcement is selected from the groupconsisting of glass, carbon, titanium, aluminum, stainless steel, talc,mica, and combinations comprising at least one of the foregoing; and/or(vi) the reinforcement comprises carbon fibers; and/or (vii) the secondplastic material comprises a thermoset; and/or (viii) wherein thethermoset is epoxy.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other (e.g., ranges of“up to 25 wt. %, or, more specifically, 5 wt. % to 20 wt. %”, isinclusive of the endpoints and all intermediate values of the ranges of“5 wt. % to 25 wt. %,” etc.). “Combination” is inclusive of blends,mixtures, alloys, reaction products, and the like. Furthermore, theterms “first,” “second,” and the like, herein do not denote any order,quantity, or importance, but rather are used to d one element fromanother. The terms “a” and “an” and “the” herein do not denote alimitation of quantity, and are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The suffix “(s)” as used herein is intended toinclude both the singular and the plural of the term that it modifies,thereby including one or more of that term (e.g., the film(s) includesone or more films). Reference throughout the specification to “oneembodiment”, “another embodiment”, “an embodiment”, and so forth, meansthat a particular element (e.g., feature, structure, and/orcharacteristic) described in connection with the embodiment is includedin at least one embodiment described herein, and may or may not bepresent in other embodiments. In addition, it is to be understood thatthe described elements may be combined in any suitable manner in thevarious embodiments.

While particular embodiments have been described, alternatives,modifications, variations, improvements, and substantial equivalentsthat are or may be presently unforeseen may arise to applicants orothers skilled in the art. Accordingly, the appended claims as filed andas they may be amended are intended to embrace all such alternatives,modifications variations, improvements, and substantial equivalents.

What is claimed is:
 1. An energy absorber, comprising: a plurality ofcrush lobes, wherein the crush lobes include a base and sides extendingfrom the base to an outer wall, wherein the base, sides and outer wallcomprise a first thermoplastic material; and a composite insert in theenergy absorber, wherein the insert comprises a second plastic materialand reinforcement, wherein the second plastic material comprises atleast one of polypropylene, polybutylene terephthalate, and polyamide,and wherein the composite insert is a separate element that is disposedin an area of the crush lobes, wherein the area is the side and/or theouter wall, and wherein the area has an area height and an area width;wherein the reinforcement comprises continuous fibers.
 2. The energyabsorber of claim 1, wherein the reinforcement comprises glass.
 3. Anenergy absorber, comprising: a plurality of crush lobes, wherein thecrush lobes include a base and sides extending from the base to an outerwall, wherein the base, sides and outer wall comprise a firstthermoplastic material; and a composite insert in the energy absorber,wherein the insert comprises a second plastic material andreinforcement, wherein the second plastic material comprises at leastone of polypropylene, polybutylene terephthalate, and polyamide, andwherein the composite insert is a separate element that is disposed inan area of the crush lobes, wherein the area is the side and/or theouter wall, and wherein the area has an area height and an area width;wherein the area has a volume and wherein the insert occupies less thanor equal to 65% of the volume.
 4. The energy absorber of claim 1,wherein the area has a height “h”, a thickness, and a width “w”, andwherein the composite insert has an insert height that is less than orequal to 90% of the area height, and has an insert width that is greaterthan or equal to 30% of the area width.
 5. The energy absorber of claim1, wherein the insert height is 20% to 70% of the area height and theinsert width is 40% to 75% of the area width.
 6. The energy absorber ofclaim 1, wherein the first material comprises at least one ofpolypropylene, polybutylene terephthalate, and polyamide.
 7. The energyabsorber of claim 6, wherein the first material comprises polypropylene.8. The energy absorber of claim 6, wherein the first material comprisesat least one of polybutylene terephthalate and polyamide.
 9. The energyabsorber of claim 6, wherein the second material comprises polybutyleneterephthalate.
 10. The energy absorber of claim 6, wherein the secondmaterial comprises polyamide.
 11. The energy absorber of claim 6,wherein the second material comprises polypropylene.
 12. The energyabsorber of claim 1, wherein the second material comprises at least oneof polypropylene, polybutylene terephthalate, and polyamide.
 13. Theenergy absorber of claim 1, wherein the second material comprisespolypropylene.
 14. A corner energy absorber, comprising: a plurality oflayers with a plurality of ribs connecting the layers, wherein thelayers and ribs comprise a first thermoplastic material, wherein thefirst thermoplastic material comprises at least one of polypropylene,polybutylene terephthalate, and polyamide; a composite insert comprisinga second plastic material and reinforcement, wherein the second plasticmaterial comprises at least one of polypropylene, polybutyleneterephthalate, and polyamide, and wherein the composite insert is aseparate element that is disposed in the layers, the ribs, or both;wherein the reinforcement comprises continuous fibers.
 15. The cornerenergy absorber of claim 14, wherein the reinforcement comprises glassfibers.
 16. The corner energy absorber of claim 14, wherein the firstmaterial comprises polypropylene.
 17. The corner energy absorber ofclaim 14, wherein the second material comprises polypropylene.
 18. Thecorner energy absorber of claim 14, wherein the second materialcomprises at least one of polybutylene terephthalate and polyamide.